This invention relates to compensation for a combined motor and transformer structure which offers space and cost savings and other advantages over the use of separate step down transformers and conventional motors used in combination in certain applications. More particularly, it relates to compensation for a continuous stepped down voltage output for driving oven controls and displays from a combined transformer and switchable motor.
Conventional microwave ovens have traditionally utilized both conventional and separate step down transformers and conventional AC motors to provide a stepped down voltage and power for a fan. Because fairly large stacks of laminations and associated windings are necessary to accomplish their respective functions, the multiplicity of windings and laminations results in increased cost and weight in devices requiring both a motor and a continuous output transformer.
Although there have been combined motor and transformer structures in the prior art, none of the structures known permit the continuous supply of output voltage from the transformer independent of whether the motor is either running or stopped. In those structures, the transformer secondary winding was typically wound over the motor winding so that the secondary transformer winding would only carry a voltage at times when the motor was in operation.